Skip to main content

Angular Virtual Scrolling | Module Drag Drop | 8,9,10,11,12

Virtual Scrolling has been added to CDK, loading and unloading elements from the DOM based on the visible parts of a list, and making it possible to build very fast experiences for users with very large scrollable lists.

The <cdk-virtual-scroll-viewport> displays large lists of elements performance by only rendering the items that fit on-screen.

Virtual scrolling is different from strategies like infinite scroll where it renders a set amount of elements and then when you hit the end renders the rest.

Firstly, we need to install the Angular CDK package to import the ScrollingModule module.

Install the module using  NPM - npm install @angular/cdk@latest

Table of Contents -
1.      To Install the angular CDK package
2.      To Import the ScrollingModule module
3.      Example
4.      Result

Example - Open the terminal window and execute the above command -


Import the ScrollingModule module -
import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';

import { AppRoutingModule } from './app-routing.module';
import { DataTablesModule } from 'angular-datatables';

//Scrolling Module
import { ScrollingModule } from '@angular/cdk/scrolling';

import { AppComponent } from './app.component';

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    AppRoutingModule,
    DataTablesModule,
    ScrollingModule //Scrolling Module
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }


Added the Scroll Items for scrolling your Items - app.component.ts
import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent {
  title = 'Angular 7 New Features – Virtual Scrolling and Drag and Drop Example';
  scrollItems: number[] = [];

  constructor() {
    for (let index = 1; index < 99000; index++) {
      this.scrollItems.push(index);
    }
  }
}

The code for HTML DOM  - app.component.html
<h2> {{title}}</h2>
<h4>Virtual Scrolling Example -</h4>
<cdk-virtual-scroll-viewport class="viewport-section"  itemSize="100">
   <div class="item-section" *cdkVirtualFor="let item of scrollItems">Your Item Row{{item}}</div>
</cdk-virtual-scroll-viewport>


And CSS  - app.component.css
.viewport-section {
    height: 200px;
    width: 90%;
    border: 1px solid rgb(169,169,169)
  }
  
  .item-section {
    padding: 15px;
    background: rgb(192,192,192);
    margin-bottom: 1px;
    text-align: center;
    font-size: 15px;
  }


By Anil Singh | Rating of this article (*****)

Popular posts from this blog

nullinjectorerror no provider for httpclient angular 17

In Angular 17 where the standalone true option is set by default, the app.config.ts file is generated in src/app/ and provideHttpClient(). We can be added to the list of providers in app.config.ts Step 1:   To provide HttpClient in a standalone app we could do this in the app.config.ts file, app.config.ts: import { ApplicationConfig } from '@angular/core'; import { provideRouter } from '@angular/router'; import { routes } from './app.routes'; import { provideClientHydration } from '@angular/platform-browser'; //This (provideHttpClient) will help us to resolve the issue  import {provideHttpClient} from '@angular/common/http'; export const appConfig: ApplicationConfig = {   providers: [ provideRouter(routes),  provideClientHydration(), provideHttpClient ()      ] }; The appConfig const is used in the main.ts file, see the code, main.ts : import { bootstrapApplication } from '@angular/platform-browser'; import { appConfig } from ...

List of Countries, Nationalities and their Code In Excel File

Download JSON file for this List - Click on JSON file    Countries List, Nationalities and Code Excel ID Country Country Code Nationality Person 1 UNITED KINGDOM GB British a Briton 2 ARGENTINA AR Argentinian an Argentinian 3 AUSTRALIA AU Australian an Australian 4 BAHAMAS BS Bahamian a Bahamian 5 BELGIUM BE Belgian a Belgian 6 BRAZIL BR Brazilian a Brazilian 7 CANADA CA Canadian a Canadian 8 CHINA CN Chinese a Chinese 9 COLOMBIA CO Colombian a Colombian 10 CUBA CU Cuban a Cuban 11 DOMINICAN REPUBLIC DO Dominican a Dominican 12 ECUADOR EC Ecuadorean an Ecuadorean 13 EL SALVA...

How To convert JSON Object to String?

To convert JSON Object to String - To convert JSON Object to String in JavaScript using “JSON.stringify()”. Example – let myObject =[ 'A' , 'B' , 'C' , 'D' ] JSON . stringify ( myObject ); ü   Stayed Informed –   Object Oriented JavaScript Interview Questions I hope you are enjoying with this post! Please share with you friends!! Thank you!!!

Encryption and Decryption Data/Password in Angular

You can use crypto.js to encrypt data. We have used 'crypto-js'.   Follow the below steps, Steps 1 –  Install CryptoJS using below NPM commands in your project directory npm install crypto-js --save npm install @types/crypto-js –save After installing both above commands it looks like  – NPM Command  1 ->   npm install crypto-js --save NPM Command  2 ->   npm install @types/crypto-js --save Steps 2  - Add the script path in “ angular.json ” file. "scripts" : [                "../node_modules/crypto-js/crypto-js.js"               ] Steps 3 –  Create a service class “ EncrDecrService ” for  encrypts and decrypts get/set methods . Import “ CryptoJS ” in the service for using  encrypt and decrypt get/set methods . import  {  Injectable  }  from ...

Angular Testing Questions and Answers | 9, 8, 7, 6

What Is Testing? The testing is a tools and techniques for a unit and integration testing Angular applications . Why Test? Tests are the best ways to prevent software bugs and defects. How to Setup Test in Angular Project? Angular CLI install everything you need to test an Angular application. This CLI command takes care of Jasmine and karma configuration for you. Run this CLI command- ng test The test file extension must be “.spec.ts” so that tooling can identify the test file. You can also unit test your app using other testing libraries and test runners. Types of Test – The all great developer knows his/her testing tools use. Understanding your tools for testing is essential before diving into writing tests. The Testing depends on your project requirements and the project cost. The types of Testing looks like - 1.       Unit Test 2.       Integration Test 3.       En...